1. Field of the Invention
This invention relates to a network game system for providing content through a network and in particular to a technical field of a network game system for providing a program corresponding to basic content of a network game consisting of the basic content and relevant content and later providing the relevant content through a network.
2. Description of the Related Art
Hitherto, it has been common practice to provide game content using a record medium such as a CD-ROM as a game operating in a personal computer. In this case, the user previously gets the CD-ROM, etc., sets the CD-ROM, etc., in the personal computer, and operates a recorded program, so that the user can play any desired game.
On the other hand, an environment in which a game is operated without using any record medium such as a CD-ROM is implemented with the recent rapid wide spread use of the Internet. That is, in addition to distributing of game content to the user via the Internet, a network game for enabling an indefinite number of users to access a specific address and get involved in the game is becoming widespread.
To operate a game using a record medium such as a CD-ROM in the general way as described above, the game content is fixedly determined depending on the program and thus it is difficult to realize a game rich in variety.
On the other hand, to use the Internet as described above, it is difficult to reflect the action and the situation of each user on the game content for realizing a game rich in variety although the game content is independent of the program recorded on the record medium. If the specific address on the Internet is known by a malicious person, it is feared that he or she may make unauthorized access to the specific address.